Also, shouldn't this be community wiki...?
–
Harrison BrownOct 21 '09 at 21:57

4

@harrison: yes. @Justin: please make these kinds of posts (anything where you say "one answer per post") community wiki in the future. Do not just wait for a moderator to forcibly convert it to community wiki.
–
Anton GeraschenkoOct 21 '09 at 22:51

This isn't purely a math video, it's an interview with Peter Woit and it is something of a summary of the main issues discussed on his blog and in his book. He talks about math vs. physics culture, especially the string theory community.

Richard Feynman gave the 1964 Messenger Lectures at Cornell University --- this is an endowed lecture series to which a number of famous scholars have been invited, including several physicists. His lectures were recorded, and Bill Gates bought the rights to them and has provided them to the public for free.

The content is mostly designed for a general audience, so if you have never learned physics you will learn something. And if you have studied plenty of physics already, you will be pleased to see the master at work in his prime. I very much enjoyed watching it.

I am quite surprised to see Dan Freed's lecture of Hodge Conjecture has not been mentioned. (Although it is an old thread I believe this should be in here. Before there was a QuickTime video but I am grateful to find that it has been youtubed.)

As of today, the digitized tapes of CBMS Lectures on Probability Theory and Combinatorial by Michael Steele are online. I heartily recommend them — the style is informal, but educating: there are jokes, juggling lessons, speculations about the stock market, and all of these amidst beautiful mathematics.

The University of New South Wales in Sydney has an eLearning channel on YouTube that contains lectures on a number of topics, including Algebraic Topology, Calculus, and Linear Algebra. Some computing and engineering topics are covered as well.